The Investigation Of Subclinical Mastitis In Major Dairy Goat Brkhding Provinces Of China And The Establishment Of Multiplex PCR Assay For Pathogens

Mastitis is the most frequent and harmful disease in dairy goat, which causes significant economic loss in livestock breeding and severe food security crisis in goat milk and milk products. In the last few years, people did not pay much attention to the dairy goat mastitis. With the development of the severity and increasing numbers of dairy goat, dairy goat mastitis also more and more receives takes. While in the major dairy goat breeding areas of China, such as Shaanxi, Shandong and Yunnan province, the prevalence and the pathogen of dairy goat mastitis has not been described clearly. And these issues may play a key role in limiting the development and implementation of the prevention and treatment about mastitis. In the present study, the investigations of the major pathogenic bacteria species and the morbidity of subclinical mastitis in the major dairy goat breeding areas of China were performed to provide foundations for the prevention and treatment in dairy goat mastitis. The main content of this study included the epidemiological investigation and the study on species of pathogens in dairy goat mastitis. According to the breeding situation of the major breeding areas of China, through enquiry, detection of milk somatic cell number, isolation and identification of bacterial strains, the epidemiological investigation was performed in FuPing of Shaanxi province, QingDao and WeiHai of Shandong province and KunMing, ShiLin and LuXi of Yunnan province. The multiplex PCR assay established in this study was used to identify the pathogenic species of bacteria from different areas, and the results can be concluded as follows:1. In general, the average morbidity of subclinical mastitis in dairy goat was about43.7%, and Shaanxi, Shandong, Yunnan province was43.7%,45.4%,50.9%and35.3%respectively. The average relevance ratio in QingDao, WeiHai, KunMing, ShiLin and LuXi was50.3%,55.0%,37.8%,33.0%and37.5%respectively.2. A multiplex PCR assay was established, which was a novel method for the detecting of coagulase-negative staphylococci (CNS), Streptococcus, Staphylococcus aureus(S. aureus) and Escherichia coli (E.coli) form the milk samples of dairy goat simultaneously.3. The proportion of CNS, S. aureus, E. coli and streptococcus was55%,17%,16%and12%respectively in the pathogens causing subclinical mastitis of dairy goat in China. In addition, the proportion of Staphylococcus epidermidis (S. epidermidis), Staphylococcus chromogenes(S. chromogenes) and others was47%,36%and17%respectively in the CNS.Conclusion:In China, the average morbidity of subclinical mastitis in dairy goat was high, and the morbidity rate was slightly different due to the breeding environment and pattern in different provinces. The most important pathogens causing subclinical mastitis in dairy goat was S. epidermidis, S. chromogenes, S. aureus, E. coli, and Streptococcus. Other pathogens had a small percentage accounts. A multiplex PCR assay with a high diagnostic sensitivity and specificity was also established in this study.